1. Field of the Invention
The present invention relates generally to seals for use in subterranean wellbores, and specifically to metal-to-metal seals.
2. Description of the Prior Art
A variety of conventional wellbore tools which seal, pack, hang, and connect with or between concentrically nested wellbore tubular members are set into position by application of axial forces to the tool, such as, for example, by either lifting up on a tubular string to lessen the load on a tool, or by applying a selected amount of set down weight to the tubular string, to cause selected components to move relative to one another. For example, liner hangers frequently include slip and cone assemblies which are loaded to cause a portion of the assembly to come into gripping engagement with a wellbore selected surface. For alternative example, packers frequently include elastomeric sleeves which are compressed and energized to urge the sleeve into sealing engagement with a selected wellbore surface.
Conventional metal-to-metal wellbore seals are typically structurally complicated devices, often including a number of interlocking components that are held together by threaded and other couplings. In the harsh conditions frequently encountered in oil and gas wellbores, tool components which include potential leakage paths, such as threaded couplings, are subject to deterioration and eventual failure after prolonged exposure to high temperatures, high pressures, and corrosive fluids.
Such structurally complicated setting and loading devices are likewise subject to eventual deterioration and failure due to any exposure of couplings, interfaces, or linkages to harsh wellbore conditions of high temperatures and pressures and corrosive fluids.